ca.nrc.cadc.io.NoisyBufferedInputStream Maven / Gradle / Ivy
Show all versions of cadc-util Show documentation
/*
************************************************************************
******************* CANADIAN ASTRONOMY DATA CENTRE *******************
************** CENTRE CANADIEN DE DONNÉES ASTRONOMIQUES **************
*
* (c) 2016. (c) 2016.
* Government of Canada Gouvernement du Canada
* National Research Council Conseil national de recherches
* Ottawa, Canada, K1A 0R6 Ottawa, Canada, K1A 0R6
* All rights reserved Tous droits réservés
*
* NRC disclaims any warranties, Le CNRC dénie toute garantie
* expressed, implied, or énoncée, implicite ou légale,
* statutory, of any kind with de quelque nature que ce
* respect to the software, soit, concernant le logiciel,
* including without limitation y compris sans restriction
* any warranty of merchantability toute garantie de valeur
* or fitness for a particular marchande ou de pertinence
* purpose. NRC shall not be pour un usage particulier.
* liable in any event for any Le CNRC ne pourra en aucun cas
* damages, whether direct or être tenu responsable de tout
* indirect, special or general, dommage, direct ou indirect,
* consequential or incidental, particulier ou général,
* arising from the use of the accessoire ou fortuit, résultant
* software. Neither the name de l'utilisation du logiciel. Ni
* of the National Research le nom du Conseil National de
* Council of Canada nor the Recherches du Canada ni les noms
* names of its contributors may de ses participants ne peuvent
* be used to endorse or promote être utilisés pour approuver ou
* products derived from this promouvoir les produits dérivés
* software without specific prior de ce logiciel sans autorisation
* written permission. préalable et particulière
* par écrit.
*
* This file is part of the Ce fichier fait partie du projet
* OpenCADC project. OpenCADC.
*
* OpenCADC is free software: OpenCADC est un logiciel libre ;
* you can redistribute it and/or vous pouvez le redistribuer ou le
* modify it under the terms of modifier suivant les termes de
* the GNU Affero General Public la “GNU Affero General Public
* License as published by the License” telle que publiée
* Free Software Foundation, par la Free Software Foundation
* either version 3 of the : soit la version 3 de cette
* License, or (at your option) licence, soit (à votre gré)
* any later version. toute version ultérieure.
*
* OpenCADC is distributed in the OpenCADC est distribué
* hope that it will be useful, dans l’espoir qu’il vous
* but WITHOUT ANY WARRANTY; sera utile, mais SANS AUCUNE
* without even the implied GARANTIE : sans même la garantie
* warranty of MERCHANTABILITY implicite de COMMERCIALISABILITÉ
* or FITNESS FOR A PARTICULAR ni d’ADÉQUATION À UN OBJECTIF
* PURPOSE. See the GNU Affero PARTICULIER. Consultez la Licence
* General Public License for Générale Publique GNU Affero
* more details. pour plus de détails.
*
* You should have received Vous devriez avoir reçu une
* a copy of the GNU Affero copie de la Licence Générale
* General Public License along Publique GNU Affero avec
* with OpenCADC. If not, see OpenCADC ; si ce n’est
* The buffer size may be different from the reporting size (number of bytes
* between notification events). However, notification will occur at most once
* per chunk, so the reporting size can't effectively be smaller than the buffer
* size.
*
*
* @version 0.1
* @author Patrick Dowler
*/
public class NoisyBufferedInputStream extends BufferedInputStream implements NoisyStream {
private long totalBytes = 0;
private long bytes = 0;
private int blocks = 0;
private int reportSize = 4096; // default 4K report size
private List listeners = new ArrayList();
/**
* Constructor. Uses default buffer size of BufferedInputStream and default
* reporting block size (4K).
*/
public NoisyBufferedInputStream(InputStream in) {
super(in);
}
/**
* Constructor. Uses specified buffer size for BufferedInputStream and default
* reporting block size (4K).
*/
public NoisyBufferedInputStream(InputStream in, int bufSize) {
super(in, bufSize);
}
/**
* @return number of bytes read/written by the stream
*/
public long getByteCount() {
return reportSize * blocks + bytes;
}
/**
* Sets the size increment between reporting events. Listeners are notified if
* more than numbytes have been read from the stream so far.
*/
public void setReportSize(int numbytes) {
bytes = getByteCount();
blocks = 0;
reportSize = numbytes;
doit(); // recompute blocks and bytes
}
/**
* Adds a new listener and immediately notifies the new listener by calling its
* update method.
*/
public void addListener(NoisyStreamListener listener) {
listeners.add(listener);
listener.update(this);
}
/**
* Remove the specified listener.
*/
public void removeListener(NoisyStreamListener listener) {
listeners.remove(listener);
}
/**
* Remove all listeners.
*/
public void removeListeners() {
listeners.clear();
}
/**
* Notify all listeners that something changed and they should check the state
* of the stream.
*/
protected void notifyListeners() {
Iterator i = listeners.iterator();
while (i.hasNext()) {
NoisyStreamListener n = (NoisyStreamListener) i.next();
n.update(this);
}
}
public int read() throws IOException {
int i = super.read();
if (i != -1) {
bytes++;
doit();
}
return i;
}
public int read(byte[] buf, int off, int len) throws IOException {
int i = super.read(buf, off, len);
if (i != -1) {
bytes += i;
doit();
}
return i;
}
/**
* Closes the input stream and notifies all listeners.
*/
public void close() throws IOException {
notifyListeners();
super.close();
}
/**
* Resets the stream to the position at the last mark. Listeners will get
* notified of the change if enough bytes remain "read".
*/
public void reset() throws IOException {
// un-count the bytes if rewinding occurs
if (markpos >= 0 && pos > markpos) {
int back = pos - markpos;
bytes = getByteCount() - back;
blocks = 0;
doit();
}
super.reset();
}
private void doit() {
boolean changed = false;
while (bytes >= reportSize) {
long b = bytes / reportSize;
blocks += (int) b;
bytes -= b * reportSize;
changed = true;
}
if (changed) {
notifyListeners();
}
}
}